As shown in FIGS. 5 and 6, conventional laminated electronic components include a component having a coil formed in an element body by laminating magnetic material layers 51A to 51F and conductor patterns 52A to 52E and by spirally connecting the conductor patterns 52A to 52E between the magnetic material layers with lead-out ends of the coil led out to longitudinal-direction side surfaces of the element body so that the coil is connected between external terminals 55, 56 formed on the longitudinal-direction side surfaces of the laminated body and four surfaces adjacent to these side surfaces.
In recent years, because of miniaturization and higher functionality of mobile devices on which this kind of electronic components is mounted, the number of electronic circuits required for these devices has increased and an area of a mounting board has become smaller. Accordingly, electronic components used for these devices are required to be reduced in size and thickness. Furthermore, minimization of land patterns for mounting and minimization of distance between adjacent electronic components are performed on mounting boards of these devices so as to mount the electronic components at higher density, and electronic components to be mounted on the mounting boards of these devices must be mounted at high density.
The conventional laminated electronic components have external terminals formed on the longitudinal-direction side surfaces of the laminated body and four surfaces adjacent to these side surfaces and therefore have a problem that a solder bridge is formed between the external terminals of adjacent electronic components due to a solder fillet at the time of mounting and soldering on a mounting board, a positional displacement of a mounting position at the time of mounting on the mounting board, etc., causing a short circuit. Therefore, it is difficult to mount the electronic components on a mounting board on which the components are mounted at a high density as described above.
To solve such a problem, a laminated electronic component having external terminals formed on the longitudinal-direction side surfaces of the element body and four surfaces adjacent to these side surfaces is covered with an insulator film except a bottom surface (see, e.g., Japanese Laid-Open Patent Publication No. 2012-256758).
However, in such a conventional laminated electronic component, since the thickness of the insulator film is added to the element dimension, the shape of the element body must be made smaller by the thickness of the insulator film, and the component has a problem that the desired inductance and DC superimposition characteristics are difficult to ensure. Additionally, such a conventional laminated electronic component has a problem that since the insulator film is formed after the external terminals are formed, it is difficult to form the insulator film accurately, and that if the insulator film goes around to the bottom surface, the component easily deviates from a land pattern of a mounting board at the time of mounting.
On the other hand, as shown in FIGS. 7 and 8, magnetic material layers 71A to 71E are provided with conductor patterns 72A to 72E and conductors 73, 74 penetrating the magnetic material layers, and a coil is formed in a element body by laminating the magnetic material layers 71A to 71F and the conductor patterns 72A to 72E and by spirally connecting the conductor patterns 72A to 72E between the magnetic material layers in the element body provided with the conductors 73, 74 such that both ends of the coil are led out by the conductors 73, 74 to a bottom surface of the element body and connected to external terminals 75, 76 formed on the bottom surface of the element body (see, e.g., Japanese Examined Patent Application Publication No. 62-29886).